Not Applicable
The present invention relates to drilling head assemblies used in drilling oil wells and the like. More particularly, this invention relates to reduction of erosion in bowls of drilling head assemblies.
The present invention relates to and improves upon prior art drilling head assemblies, such as the drilling head assembly of U.S. Pat. No. 3,400,938 (Williams), the disclosure of which is incorporated herein by reference. Prior art drilling head assemblies disclose the use of a stationary housing or bowl member. The bowl member has open upper and lower ends, and a central receiving cavity configured to receive and support a rotary sealed bearing assembly. The configuration of the bowl includes a means for attaching the device to a casing or other oil and gas well component at the surface of the well bore, such as by a conventional flange and bolt arrangement. The bowl member has a discharge nozzle extending therefrom. The discharge nozzle fluidly communicates with the receiving cavity, such that during drilling operations, fluid and airborne particles discharged from the drill string pass through the bowl.
A rotary sealed bearing assembly is supported by the stationary housing. The sealed bearing assembly includes a rotatable sleeve member housed within a stationary sleeve member. The rotatable sleeve member includes a means for driving a drill string via a drilling Kelly, as detailed in e.g. U.S. Pat. No. 3,400,938. A bearing assembly is interposed between the rotatable and stationary sleeves. A chamber is provided between the sleeves for receiving a lubricating fluid. Upper and lower sealing members are provided for preventing leakage of fluid from the fluid chamber and bearing assembly. An auxiliary seal means can be provided for additional protection of the bearing assembly. A quick release clamp is provided for facilitating installation and assembly of the drilling head assembly at a well site. The clamp is configured to encircle an upper end of the stationary housing and an outer circumference of the stationary sleeve.
One problem encountered with prior art drilling head assemblies is erosion of the bowl component of the apparatus. During drilling operations, fluids and airborne solids are discharged from the well bore through the bowl and the discharge nozzle of the bowl, typically at high velocities and pressures. The discharged fluids and airborne solids erode the inner surface of the bore and the bore nozzle. During drilling operations, the discharged fluids and airborne solids tend to form vortexes or other regular patterns of flow within the bowl. These vortexes and flow patterns accelerate erosion in particular regions of the bore and bore nozzle.
Similar erosion problems are encountered in centrifuge pumps. To reduce or eliminate erosion, centrifuge pumps are provided with interior diverters or baffles that serve to break up the flow of fluids, minimizing the formation of vortexes and other patterns of flow. As far as the inventor is aware, diverters have not been applied to the drilling head assembly art. Accordingly, there is a need for a bowl member and a drilling head assembly having the following characteristics and properties.
It is an object of the invention to provide an erosion resistant bowl apparatus for use in a drilling head assembly.
It is an object of the invention to provide a drilling head assembly that includes diverters for breaking up the flow of current within the drilling head assembly and thereby preventing erosion of the bowl and discharge nozzle components of the drilling head assembly.
It is another object of the invention to provide a rotary sealed bearing assembly for a drilling head assembly that does not require preloading of the bearing assemblies.
It is still another object of the invention to provide an improved means of sealing bearing assemblies to prevent loss of lubricant.
These and other objects and advantages of the invention shall become apparent from the following general and preferred description of the invention.
Accordingly, an erosion resistant bowl apparatus for use in a drilling head assembly for drilling operations is provided comprising, generally, a bowl member, the bowl member having a central receiving cavity configured to receive a rotary sealed bearing assembly, the bowl member having a discharge nozzle extending therefrom, the discharge nozzle fluidly communicating with the receiving cavity, and at least one diverter member extending from an inner surface of the receiving cavity of the bowl, the diverter member formed and configured to disrupt patterns of fluid flow within the bowl during drilling operations.
The apparatus preferably includes at least one nozzle diverter member extending from an inner surface of the discharge nozzle. First and a second nozzle diverters may extend from an inner surface of the discharge nozzle, and the first and second nozzle diverters are preferably positioned on opposing upper and lower inner surfaces of the discharge nozzle.
A plurality of diverter members preferably extend from an inner surface of the receiving cavity of the bowl, the diverter members formed and configured to disrupt patterns of fluid flow within the bowl during drilling operations. A central diverter preferably extends from an inner surface of the receiving cavity, the central diverter positioned at about 180 degrees from a central axis of the discharge nozzle. A pair of first and second lower diverters preferably extend from a lower portion of the inner surface of the receiving cavity on opposing sides of the discharge nozzle. A pair of first and second upper diverters preferably extend from an upper portion of the inner surface of the receiving cavity on opposing sides of the discharge nozzle. The upper diverters are preferably closer to the central diverter than the lower diverters. In a preferred embodiment, the first and second lower diverters are positioned at about 45 and 315 degrees, respectively, relative to the central axis of the discharge nozzle, while the first and second upper diverters are positioned about 60 and 300 degrees, respectively, relative to the central axis of the discharge nozzle.
The erosion resistant bowl is used in a rotary drilling head assembly for a well bore. A rotary sealed bearing assembly is supported by the bowl. The rotary sealed bearing assembly comprises a rotatable sleeve member, a stationary sleeve member surrounding the rotatable sleeve, a chamber provided between the stationary sleeve and the rotatable sleeve for receiving a lubricating fluid, a bearing means interposed between the stationary sleeve and the rotatable sleeve and disposed within the chamber, an upper and lower sealing means carried by the stationary sleeve and providing a seal for the chamber to substantially preclude leakage of fluid into or out of the chamber.